1. Field of the Invention
This invention relates generally to convertible railroad cars and, more specifically, to a rail car that is convertible from a flatbed rail car to a bulk storage freight car through utilization of collapsible containers that are stored beneath the bed of the rail car.
2. Description of the Prior Art
Briefly, the concept of convertible freight hopper cars is known in the art as evidenced by the following patents:
Austill U.S. Pat. No. 3,595,175 shows a hopper box-like or freight car for transferring freight in granular or bulk form with the car including a grate over the opening of the hopper and bulkheads within the car to direct the granular material to the hoppers. The conveyor in the car is enclosed and contains essentially a large compartment for granular freight material.
The Dorey U.S. Pat. No. 2,648,293 shows a convertible railway car having movable floor sections arranged to swing on axes so as to divide the car into various compartments with the car containing bottom discharge doors.
The Kobarynka, et al. U.S. Pat. No. 1,975,955 shows a convertible car with folding doors that permit the car to be used as a grain conveying car or an ordinary box car. The folding doors are placed over the hoppers at the bottom of the car to produce the box car mode and are folded along the side to produce the grain conveying car mode.
The Natali U.S. Pat. No. 1,935,057 shows an invention similar to the Kobarynka, et al. U.S. Pat. No. 1,975,955 with the Natali patent box car having pivotal doors over the hoppers to permit bulk material to be directed through the hopper.
The Pflager U.S. Pat. No. 2,049,617 also shows a hopper car having hinged floor sections which fold over his hoppers.
The Fitch U.S. Pat. No. 2,071,620 shows a flatbed carrier with folding sides for use as either a flatcar or a hopper car.
The Krug U.S. Pat. No. 3,800,712 shows a flatcar having means for mounting standard containers on the top of a flatbed car so that standard containers can be used to transport material.